by viking » Fri Mar 16, 2018 3:12 pm
I did the math some years ago but forget the details. At 4,000 RPM a 460 is sucking far less than 600 cfm through the carb. So the size is good. (Some will argue whether the Holley is a good choice. I read good and bad about everything. Clear float bowls might be nice.) You can get a new marine replacement online. (Search on "Marine Holley 4160 for Ford 460".) Rebuild kits are available at O'Reilly, but typically have the small accelerator pump diaphragm appropriate to a 351. My understanding is "marine" means the overflow tubes turn down into the carb to prevent spill into bilge.
I don't know whether throttle body fuel injection will help performance. I've never compared. But odds are good.
All carbed engines have a disadvantage with exhaust below the water line. When you shut the engine off, the engine spins down and continues sucking fuel through the cylinders and into the exhaust manifolds. This creates a perfect fuel/air mixture in your exhaust. And it is hot. If the engine should decide to diesel, it can be fueled from the exhaust and run backwards for a few cycles. This will suck water into the engine. To avoid this, always turn the engine off after allowing it to idle/cool for a while. It is suggested that to clear a stick from the pump, you can back into current, then shut the engine off and let the current maybe clear the stick. This is great with fuel injection because fuel stops with the ignition. However, with a carb there's the risk of hydro-lock, so it's not a great idea.
Anyway, I'd give fuel injection serious consideration, but only if it has good reliability reviews.